Circular knitting machine



Dec. 10, 1935. P. A. BENTLEY ET AL 2,023,633

CIRCULAR KNITTING MACHINE Filed June 2, 1932 4 Sheets-Sheet 1 INVEN rams-I Dem 1935- P. A. BENTLEY ET AL CIRCULAR KNITTING MACHINE Filed June 2, 1932 ram 263% $6 P. A. BENTLEY ET AL CIRCULAR KNITTING MACHINE Dec. 10, 1935.

Filed June 2, 1932 4 Sheets-Sheet 3 Dec. 10, 1935. P. A. BENTLEY El AL CIRCULAR KN ITTING MACHINE Filed June 2, 1932 4 Sheets-Sheet 4 I MUM/Tons am t 67% Patented Dec. 10, 1935 UNITED STATES PATENT OFFICE 2,023,633 I cmcumm. xm'rrmc momma ter, England Application June 2, 1932, Serial No. 615,046 In Great Britain June 9, 1931 Claims.

This invention is for improvements in or relating to circular knitting machines.

The present invention is particularly, although not exclusively, applicable to circular rib-knitting machines of the type that is characterized by having superposed needle cylinders within corresponding cam boxes and means to produce relative rotation and rotary reciprocation of the cylinders and cam boxes. This type of machine is exemplified by the machines described in the specifications of British Letters Patent Nos.

15008/1900; 242.90/1912; and 171,483.

As explained in the specification of our application Serial No. 468,168, filed July 15, 1930, it is the usual custom in half-round splicingto supply an auxiliary yarn to about half the needles in the needle circle of the machine and to float this yarn behind those needles of the needle circle which are not required to knit it into the fabric, There are certain disadvantages in thus 0 floating the auxiliary yarn and in the machine described in the last-named specification, the need for floating the yarn is obviated by the provisionin the machine of mechanism which cuts and traps the auxiliary yarn at the end of one course of the portion to be spliced and re-introduces it at the beginning of the next course of said portion.

Under certain circumstances, however, it is advantageous to be able to elect, at will, either that the auxiliary yarn shall thus be trapped and cut 'or that it shall be floated behind the needles which are not concerned with the splicing operation.

Thus when ribbed goods are being knitted, severing the yarn at each course is practically essential, as if it were floated, the floated yarn would lie around the outside of the rib needles and be very difficult to cut and withdraw by hand afterwards. Severing the yarn also has 40 obvious advantages, such as the saving of yarn and saving the necessity for cutting out floated threads by hand afterwards, but if severing at each course is done on plain goods, i. e. with all the needles in the bottom cylinder, the end of the yarn very readily comes to the outside of the fabric (a littlehandling is often suflicient to do this) although all the ends may have been inside when the fabric left the machine. The ends of the yarn, when they are severed during the knitting, are of necessity rather short as if they were long they could not be turned to the inside of the fabric and would sometimes be picked up by needles at succeeding courses, causing had work. If the yarn is floated at each course, fairly long ends can be left when cutting by hand and it has also been shown in practice that the first and last loops of auxiliary yarn are tighter and the ends less readily pull out when the yarn is floated than when it is severed. The difllculty of the ends coming to the outside of the fabric a on ribbed work is entirely overcome by making a rib needle knit the beginning and finishing ends of the yarn.

The tendency of the yarn ends to come to the outside by handling after knitting varies somewhat with the kind of yarn used and some usersof machines of the type disclosed in this application .employ the severing method for all goods and others sever on the ribbed goods and float on the plain.

A further point of importance to some users 15 is that with the floated method the trapper has very little work to do and its maintenance and setting call for-less skill and attention than is the case with the severed method.

An object of the present invention is to pro- 20 vide means whereby this choice of alternative methods of dealing with the auxiliary yarn may be obtained.

Another object of the invention is to ensure that the beginning and finishing ends of the 25 auixilary yarn shall-be of minimum length without the occurrence of unwanted engagement of the yarn or yarns by the sinkers.

The invention consists in certain features and combinations pointed out in the claims. :0

In the machine hereinafter described as illustrative of said features and combinations, the yarn-feeding device and the yarn cutting and trapping device are generally similar to the corresponding devices described in the specification 35 of our said application and,when the auxiliary yarn is being trapped and cut at each course of the knitting, act generally in a similar manner. The illustrative machine however is provided with a switch or finger piece which, when the 40 auxiliary yarn is to be floated as aforesaid instead of being trapped and cut, acts to prevent the yarn cutting and trapping device from closing upon that yarn. This finger piece can either be controlled manually or automatically from pattern mechanism of the machine. In the illustrative machine, also, it has been possible to avoid the need for the short-ribbed sinkers referred to in our said application and yet main- 50 tain a short end to the auxiliary yarn. This has been efiected by a slight alteration in the timing of the sinkers, and in the position of the auxiliary yarn feeder in relation to the yarn cutting and trapping device, as well as a slight altera- 55 tion in the position of said device relatively to the needles.

Convenient constructions of mechanism according to the present invention will now be .described, by way of example, with the aid of the accompanying drawings, and will be considered as applied to a circular rib-knitting machine of the type above mentioned and of the particular kind of that type in which the needle cylinders rotate within stationary cam boxes.

In the accompanying drawings:-

Figure 1 illustrates diagrammatically in front elevation a circular knitting machine of the type and kind just mentioned,'which machine has applied thereto yarn-feeding mechanism according to the present invention;

Figure 2 shows in plan most of the parts shown in Figure 1;

Figure 3 is a side elevation of parts shown in Figures 1 and 2;

Figure 4 shows, in plan, a portion of a sinker sleeve and sinker ring, and certain of the sinkers mounted in the tricks of the latter;

Figure 5 is a sectional elevation of parts shown in Figure 4, showing also the cam for operating the sinkers;

Figure 6 is a detail view to illustrate the position taken by a sinker in relation to a needle during a certain stage of the knitting;

Figures 7, 8, 9, 10 and 11 are diagrams illustrative of the manipulation of the yarn by the several yarn-handling devices of the machine with a view to producing in-the auxiliary yarn a loose end of minimum length;

Figure 12 is a detail view in plan of part of the mechanism for controlling the cutting and trapping of the auxiliary yarn; and

Figure 13 is a section on line I3I3 of Figure 12.

In the present construction, the feeder for the auxiliary yarn, the mechanism for operating that feeder, the cutting and trapping device, and the mechanism for moving the stitch cams for the frame needles to slacken the stitches when those needles receive the auxiliary yarn, are in general (with the exceptions which will hereinafter appear) similar to the corresponding devices in the machine (hereinafter termed the prior machine) described in the specification of our said application Serial No. 468,168 and in the normal operation of the machine operate in a generally similar manner.

As in the prior machine, the feeder 26 (Figure 2) is positioned with its yam-feeding end adjacent the gap between the upper and lower needle cylinders I4, I6 respectively, of the machine and is pivoted at 24 on a plate 22 carried at the upper end of a post 20 (Figure 3) secured in a bracket I8 mounted upon the machine frame. The feed-' er 26 is swung about its pivot 24 from an inoperative position (see Figure 2), where its yamfeeding end is closely adjacent the cutting and trapping device (indicated generally at 34) to its operative position at the yarn-feeding location, which position is determined by an adjustable stop 30 towards and against which the feeder is urged by a spiral spring 33 which surrounds the pivot stud of the feeder and has one end bearing against the support for the adjustable stop 30 and its other. end engaging a tail-piece 35 of the feeder. The feeder 26 is swung in the opposite direction by connections from a cam 60 (Figure 3) on a running shaft 62 of the machine. These connections include a bell-crank lever 64 loosely mounted upon a horizontal shaft 65 joumalled in the bracket I 8, one arm of which lever 64 is operatively connected by a push-rod 68 with a lever 10 pivoted at 13 (see Figure 2) on the bracket I8 and provided with a follower II (Figure 1) which is adapted to bear upon the cam 60. 5 The other arm of the bell-crank lever 64 extends obliquely upward and at its upper end has a vertically projecting portion, one side of which bears against the tail-piece 35 of the feeder.

Mounted upon the running shaft 62 adw jacent the cam 60 just mentioned is a second cam 16' which is engaged by a follower 'I'I (Figural) on a lever 16 mounted on a pivot pin I9. Upon this lever rests the lower end of a push rod I8, the upper end of which rod is engaged by an arm 80 secured to one end of the horizontal shaft 66. At the other end of said shaft is secured a second arm 80 (Figure 3) which overlies 2:. lug on a short lever 82 which corresponds to the lever 82 of the prior machine and like that lever is connected with the stitch cams of the frame needles, one of which cams is indicated'at I50. The stitch cams and their appurtenances are the same as those of the prior machine, so need v not be'described in detail.

In the present construction the cutting and trapping device 34 is operated by a cam 260 on the running shaft 62 of the machine. This cam engages a follower 26I on a lever 262 (Figure 2) pivoted on the pin 19 upon which lever rests the lower end of a push'rod 263 (Figure 3), the upper end of which is adapted to be engaged by a lever 264 pivoted upon the horizontal shaft 66. An arm 264 (Figures 12 and 13) projecting from the hub of this lever is connected by a wire cable 265 with one end of the lever 266 (Figure 3) that actuates the movable member of the cutting and trapping device 34. Thisactuating lever 266 is pivoted upon the body portion 261 of the cutting and trapping device, which portion is adjustably secured to a'block on the post 20 by a bolt 268, which passes through a horizontally-disposed slot 269 in said portion and is screwed into a hole in the block. The other end of the actuating lever 266 is forked as shown in Figure 3 and engages between the tines of its fork a lug projecting from the movable member of the cutting and trapping device 34. This device comprises two blades I60, I62 (see Fig. 3),50 similar to the blades I60, I62 of the prior machine, of which blades the blade I62 is secured to the body portion 261 of the device-and the blade I60, which has a slot I68 (see Figs. '7, 8 and 10) providing a cutting edge and corresponding to the slot I68 of the prior construction, slides in a guideway between the fixed blade and said body portion. These blades in the present construction are disposed at a more acute angle to the vertical than the corresponding blades of the 5 prior machine and the yarn feeding end of the feeder is located immediately adjacent to these blades as shown in Figure 2 when the feeder is in its non-feeding position.

The actuating lever 266 for the cutting and trapping device is acted upon by a torsion spring 210 which surrounds the 'pivot 2' of the lever and tends to turn the lever in a drection which tautens the wire cable 265 and closes the cutting and trapping device 34. One end of the torsion spring 210 bears upon the lever 266 (Figure 2) and its other end bears against a plate 212 which is attached to the pivot 21I by a nut threaded on the end of the pivot. By slackening the nut the plate 212 can be turned upon the pivot 2' v 2,028,633 -to vary the degree of tension of the spring 210.

To enable the wire cable 265 readily to be assembled with or removed from the parts it connects, each end of the cable terminates in a ball which rests in a cup-shaped recess in the said part (see the ball 213 at the upper end of the cable in Figure 1), the wire from the ball passing through a hole formed in the part, into which hole the wire is introduced through a slit (see the slit 2I3 in Figure 2) which extends from the outer surface of the part to the hole.

As thus far described it will be apparent that the three cams 60, I4, 260 on the running shaft 62 will operate respectively the yarn-feeder 26, the stitch cams I50, and the cutting and trapping device 34. The action of these cams upon their respective mechanisms is, however, under the control of the control drum I (Figure 1) of the machine, which, as in the prior machine, has upon it cam projections adapted, as the drum rotates, to engage and move a cam lever I04. This lever is connected by a link I06 to another lever 214 which, as it is formed from a relatively thin piece of metal, may be termed a plate lever. The plate lever is attached to the upper surface of a block 215 which carries the horizontally disposed pivot pin I9 (see Figure 2) of the two follower-carrying levers I6, 262 of the stitch-camadjusting and trapper-operating mechanisms respectively. This block 215 itself is pivotally mounted on a vertically-disposed pin 216 projecting downward from the bracket I8. A downtumed lug 211 (Figure 1) of the plate lever 214 is connected by a spiral spring 218 with a stationary part of the machine. The pull exerted by the spring 218 tends to turn the plate lever on its pivot in a direction which causes that lever to exert a thrust on the link I06 connecting it with the cam lever I04 and thus maintaining the cam lever in contact with the control drum I00. Normally, i. e. when a cam projection on the control drum is not in engagement with the cam lever, the spiral spring 218 maintains the two follower-carrying levers I6, 262 in a position in which their followers are resting upon the plain circular portions of the hubs of their respective cams I4, 260 and consequently no movement is imparted to; these levers at this time.

When, however, a cam projection (such as I02) on the drum I00 comes beneath the cam lever I04 and raises it, the plate lever is turned and swings the two follower-carrying levers I6, 262 to bring their followers into the path of the cams on the running shaft 62, so that these two levers and the parts connected with them are actuated by the cams I4, 260. At the same time a prop-lever 280 (corresponding to the lever H6 of the prior machine) which previously had kept the follower carrying lever I0 appertaining to the yarn feeder substantially in a position to which its cam on the running shaft had lifted it,

is now withdrawn (as shown in Figure 3) from contact with the lever I0 leaving that lever free to be moved by its cam.

In the present construction, the prop-lever 280 acts upon the lever I0 on that side of the pivot of that lever which is the more remote from the follower II, and sequently the prop-lever is pivoted at its upper end (i. e. at 28I) and engages the lever I0 by its lower end. The lower end of the prop-lever is slightly inclined or cam-shaped so that in its movement over the end of the lever I0, the latter is cammed to raise the follower II to an extent which is somewhat higher than that to which it is moved by the cam 60 on the running shaft 62. For purpose of adjustment the surface which is engaged by the inclined end 'of the prop-lever 280 is formed by a screw 282 threaded through the end of the lever I0. The prop-lever 280 is moved as described by connections from the plate lever 214, which connections comprise a connecting w rod 283'pivoted at one end to the prop-lever and at its other end projecting through a hole formed in an upturned lug 284 on the plate lever. A 10 compression spring 285 surrounds the connecting rod 283 and bears at one end against the upturned lug and at its other end against the prop-lever, a collar adjustably secured by a set screw 281 to the end of the rod engages the upturned lug 284 and serves as a limit-stop to the action of the spring 285. In the construction described, the thrust which is exerted upon the prop-lever to move its end from over' the lever I0, is transmitted through the compression spring 285.

Each of the three cams 14, 260, 60 on the running shaft 62, like the cams 60 and I4 of the prior machine, is adjustable as to its effective length by being formed in two adjacent portions relatively shiftable around the shaft, the respective followers which engage these cams being wide enough to engage both portions. Also as in the prior machine, the contacting portions of the levers which engage the upper ends of the push rods 68, 18, 263 before mentioned are each constituted, for purposes of adjustment, by a screw threaded in the lever.

The mechanism as thus far described will operate in a manner similar to that in which operates the corresponding mechanism of the prior machine, that is to say the auxiliary yarn will be cut and trapped each time the yarn feeder 26 moves to its inoperative position. To en-- able the machine to be adjusted so that the auxiliary yarn when not to be knitted into the fabric is not cut and trapped but merely floated behind the needles, the following mechanism is providedz-On the bracket I8 and from the bearing portion thereof between the levers 80 and 264 (see Figure 2), there projects vertically a pin upon which is pivoted a finger piece 290. This finger piece is acted upon by a torsion spring 29I (Figures 1 and 3) surrounding the pivot pin and connected at one end to the finger piece and at the other to the pin. The torsion spring 29I urges the finger piece in such a direction that a vertically-disposed screw 292 (see Figures 12 and 13) threaded through the finger piece is moved against a plate 293 which is secured to the hub of the lever 264 which constitutes part of the mechanism for operating the cutting and trapping device 34. The plate 293 is located on the same side of said hub as is the arm 264 which descends and exerts a pull on the wire cable 265 when the lever 264 is raised by its cam 260 on the running shaft 62. The plate 293 has a ledge or shelf 293 formed on it which, when the plate arrives in its lower position, is just below the level of the bottom end of the screw 292 on the finger piece 290. When the plate 293 reaches its lowermost position, the torsion spring 29I causes the lower end of the screw 292 to snap over the ledge or shelf 293 and'thus prevent a subsequent rise of the plate.

As the cutting and trapping device 34 is opened by a pull on the wire cable 265, it will be apparent that the action of the finger piece 290 and associated parts in preventing such rise of the plate v293 will result in the cutting and trapping device 34 being maintained in open position.

Any suitable means may be provided for moving the finger piece 290 against the action of the torsion spring 29I into an inactive position and for maintaining it in that position. For instance a cam projection such as the rise I03 (Figure 1) of the projection I03, on the control drum I00 may be arranged to actuate, at the desired time, a .'cam lever 294 pivoted at 295 on a relatively fixed part and having an extension 296 carrying a cam piece 291 which acting on the finger piece 290 will move it into and maintain it in its inactive position. Alternatively,'or. additionally, the finger piece may be under manual control, there being provided, for instance, a manually controlled spring catch which will hold the finger piece out of action when the finger piece-has been swung against the action of its spring into range of that catch. In the present construction, the connection between one end of the torsion spring "I and the pivot pin of the finger piece 290 is constituted by a milled-edged disc 298 to which that end of the spring is secured. This disc is secured to the top of the pivot pin by a screw 299 which when slackened permits the disc to be turned by varying the degree of tension of the spring, or to relieve the whole of that tension and swing the finger piece into an inactive position.

In the prior machine, the loose end of the auxiliary yarn formed by the part of that yarn extending from the trapper to the first needle to take the yarn is kept short by the trapper being placed close to the needle circle and the timing of the sinkers being altered to permit such locathe cutting and trapping device as compared with the timing of the operation of these parts in the prior machine. In the present construction, as

in the prior machine, the sinker-operating cam 42 (Figure 5) is arranged to give to the sinkers 36 at the location 38 (Figure 4) an early inward movement preliminary to the final inward movement which occurs at the usual time in the operation of the machine but the extent of this early inward movement in the present construction is less than in the prior machine as will be apparent from Figure '4, if this figure be compared with Figure 10 of our said application. The early inward movement of the sinkers in the present construction avoids the danger of the yarn being split or otherwise improperly engaged by some of the sinker nibs-see in this connection Figure 6 which shows the positions of a rib needle, yarn, and sinker at a stage of the inward movement of the sinker. An advantage of this arrangement is that knitting ribbed fabric is much safer than in the prior machine, as the present construction permits the employment of sinkers which are all of normal form and therefore are all capable of performing their loopholding function in a normal manner. The timing 'of opening of the cutting and trapping device 34 in the present construction is advanced in the cycle of operations of the machine, by an appro priate adjustment of the parts operating that device. In the operation of introducing an auxiliary In the present construction these yarn I40 (see Figures 7 to 11 where the main yarn is indicated at I52) into the fabric the yarn feeder 26 swings from its inoperative position (Figure 2) to its feeding position (Figure 7) laying the yarn extending between it and the trapper 34 5 across the front of the needles whereupon the leading needle I (see Figures 7, 8 and 9 takes the yarn I40 in its hook. This needle then moves along the yarn a short distance, nextthe yarn aneedle of the bottom cylinder, but if preferred,

the first needle to receive that yarn may be a needle of the upper or rib cylinder.

In the operation of the machine, assuming that the auxiliary yarn is to be trappedand cut at the end of each course of the portion to be spliced, the yarn feeder 26 swings to its feeding position causing the yarn to lie from the trapper 34, which 5 at this time is holding the yarn end, to the feeder across the front of the needles and in a position where the needles can receive the yarn. The first needle which receives the yarn, moves along the yarn a short distance and then the trapper is 3 opened to release the yarn end and the needle, in drawing its loop, uses most of the yarn extending between the needle and the yarn end as just explained. The trapper 34 now remains open while the needles are being fed with the auxiliary yarn 5 and at the end of that period closes again to cut and trap the yarn when the feeder has moved into its inoperative position just in front of the trapper and the last needle to receive the auxiliary yarn .has arrived in a position just behind 40 the trapper. The above sequence of operations is repeated at every revolution of the needle cylinders during the knitting of that portion of the work which has the auxiliary yarn introduced for a part of each course.

When the auxiliary yarn is to be floated instead of being severed as above described and the finger piece 290 is adjusted to that end, the sequence of operations, during the first course in which the auxiliary yarn I40 is introduced, 50 is the same as when that yarn was severed except that when the yarn feeder 26 swings to its inoperative position in front of the trapper 34, the trapper is not closed but remains open, and the auxiliary yarn runs from the feeder 55 through the open trapper to the needle circle and is fioated behind those needles which do not knit the auxiliary yarn into the fabric. When the auxiliary yarn is to be introduced at the next course of the knitting the feeder swings into its feeding position, remains in that position until theportion of the course to contain the auxiliary yarn is knitted, and then swings out again into its inoperative position, when the yarn runs through the open trapper as before. This series of operations is repeatedv in the succeeding courses of the knitting until the floating of the yarn is to be suspended, when the finger piece 290 which was instrumental in maintaining the trapper open, is moved, either manually or automatically, into a position in which the screw 292 in the finger piece is to one side of the ledge 293 on the plate 293,- and consequently the cutter and trapper is again brought under the influence of the appropriate cam on the running shaft and operated thereby to cut and trap the yarn.

It is to be understood, that the timing and arrangement of the parts above referred to as resulting in the production of a very short loose end of the yarn, are applicable to cases in general where a yarn is fed to the needles. For instance, such timing and arrangement are applicable to the case where the yarn introduced is a yarn which is to be substituted for another, as in striping.

We claim:--

1. A knitting-machine comprising a series of needles adapted to knit a main yarn into a fabric composed of a plurality of courses, yarn-feeding means for feeding, only to a group of adjacent needles of said series, an auxiliary yarn to be knitted together with the main yarn into the fabric by said group of needles, yarn trapping and cutting means for operating upon said auxiliary yarn, means acting automatically so to operate said yarn-feeding means and said yarn trapping and cutting means that the auxiliary yarn is fed to said group of needles, and after having been knitted into the fabric thereby, is trapped and cut in readiness again to be fed to said group of needles during the operation of said group in the formation of the next succeeding course of the fabric and adjustable means adapted to be set so as to maintain open the yarn trapping and cutting means while the yarn' feeding means continues to feed the auxiliary yarn to said group of needles only, whereby according to the setting of said adjustable means the auxiliary yarn may be cut and trapped as aforesaid or floated behind the needles which do not knit said yarn. I

2. A machine according to claim 1 including a common actuator for the auxiliary yarn feeding means and yarn trapping and cutting means,

.a yieldingly operated element in the chain of operative connections between said yarn trapping and cutting means and said actuator, and an adjustable device adapted to be set so as to engage and stop the movement of said yieldingly operated element during continued movement of said actuator whereby the operation of the yarn trapping and cutting means may be suspended while the yarn feeding means continues to feed the auxiliary yarn to said group of needles. 3. A machine according to claim 1, compris- 5 ing yarn trapping and cutting means for the auxiliary yam, a spring-operated lever connected to said means, a second lever, a cable connecting said two levers, a cam-operated lever, a push-rod connecting said cam-operated lever with said second lever, and a finger-piece adapted to be adjusted into a position where it stops the movement of said second lever.

4. A machine according to claim 1, comprising yarn trapping and cutting means for the auxiliary yarn, a spring-operated lever connected to said means, a second lever, a cable connecting said two levers, a cam-operated lever,

a push-rod connecting said cam-operated lever with said second lever, a finger-piece, a control element, and connections between said element and said finger-piece operating to move the finger-piece into a position in which it stops the movement of said second lever.

5. A knitting machine comprising a series of needles, a yarn feeder, and a yarn trapping and cutting device, which device is located closely adjacent the needle circle at the part thereof where each needle draws a loop of yarn in order that the yarn end extending between the yarn feeder and the yarn trapping and cutting device shall be drawn by the first needle to take that yarn into the loop formed by that needle and thereby form a yarn end of minimum length in the knitted fabric, means for actuating the said device to release the yarn as the needle begins to form such loop, a series of sinkers cooperating with the needles in the formation of a knitted fabric, and means whereby the sinkers are caused to execute an early movement inwardly of the 40 needle circle so as to afford room for the positioning of the yarn trapping and cutting device closely adjacent the needle circle.

PERCIVAL ARTHUR BENTLEY. CHARLES FREDERICK MANGER. CARLYLE HERBERT WAINWRIGHT. 

